Description:
This site, from Australian Broadcasting Corporation, relates how the evolution of human body lice was made possible when we developed the habit of wearing clothes some 40,000 years ago. "'This ecological differentiation [between lice which lay their eggs in the scalp and those that lay their eggs in clothes) probably arose when humans adopted frequent use of clothing,' write the researchers. Thus, an indirect measure of when our ancestors first wore clothes would have emerged by figuring out when body lice first appeared, the researchers concluded."